This paper investigates a general framework of a pushdown system with well-quasi-ordered states and stack alphabet to show decidability of reachability, which is an extension of our earlier work (Well-structured Pushdown Systems, CONCUR 2013). As an instance, an alternative proof of the decidability of the reachability for dense-timed pushdown system (in P.A.Abdulla, M.F. Atig, F. Stenman, Dense-Timed Pushdown Automata, IEEE LICS 2012) is presented. Our proof would be more robust for extensions, e.g., regular valuations with time.

Rights:

This is the author-created version of Springer, Xiaojuan Cai and Mizuhito Ogawa, Lecture Notes in Computer Science, 8475, 2014, 336-352. The original publication is available at www.springerlink.com, http://dx.doi.org/10.1007/978-3-319-07151-0_21